As many as 450 officers were part of the operation on Tuesday, executing 29 search warrants from 6am and arresting 18 men aged between 19 and 39.

Police say they are all linked to the Alameddine family, operating at the low to medium tier of a drug distribution network, rather than upper level figures that police were already targeting.

"I'm confident that we have cut the head off the snake," NSW Police Commissioner Karen Webb said.

The syndicate was responsible for the importation of drugs, all the way to street-level dealing, and recent violence stemmed directly from the battle for control of the lucrative Sydney drug market, she said.

"All of those arrested displayed considerable wealth and assets which we allege were generated entirely through the profit of drugs."

"None of those arrested today had any obvious forms of employment," Ms Webb said.

Police seized more than $250,000 in cash, prohibited weapons, drugs, firearms luxury watches and jewellery in the raids as well as 36 mobile phones which police say were being used to run a "dial-a-dealer" syndicate.

Dedicated encrypted communication devices, SIM cards, laptops, electronic storage devices, key fob remotes, car keys, CCTV systems and documentation consistent with the supply of prohibited drugs were also seized.

"These phones have been the subject of competition ... they are directly connected to a number of murders," NSW Police Assistant Commissioner Michael Fitzgerald said.

The phones were integral to the business syndicate feeding Sydneysiders' desires for cocaine, MDMA, cannabis and prescription drugs, and brought in more than $250,000 a week for the dealers.

One of the phones had the contact details of more than 700 customers.

"People were contacting that phone asking for drugs," Mr Fitzgerald said.

In July last year, Strike Force Sugarcane was created to investigate the syndicate.

Investigating police used undercover operators and other covert technologies over the last 10 months.

Tuesday's raids ran in conjunction with Taskforce Erebus, recently set up to tackle organised crime amid a spate of public place shootings.

The taskforce arrested a number of alleged members and associates of bikie gangs including Comancheros, Finks and Rebels last week.

The Comancheros is the largest criminal organisation in the country and supplied drugs to the syndicate, Mr Fitzgerald said.

Police Minister Paul Toole said the raids had dismantled "one of Sydney's most dangerous criminal networks".

"This is suburban terrorism and their activities, which jeopardises the safety of the community simply won't be tolerated," he said.

"The arrest of junior right through to senior members and associates of this group sends a very strong message to the criminal community - police are watching you."

None of the people arrested on Tuesday are believed to be responsible for murders in Sydney streets and gym foyers in recent weeks.

However, a number of them are suspects in other murders over the last two years, Mr Fitzgerald said.

Serious charges are expected to be laid regarding commercial drug supply, firearms and directing of organised crime groups.

Australian Associated Press